title: Reduction of toxicity of antimicrobial compounds by degradation processes using activated sludge, gamma radiation, and UV.
abstract: The occurrence and persistence of pharmacologically active compounds in the environment has been an increasingly important issue. The objectives of this study were to investigate the decomposition of aqueous antimicrobial compounds using activated sludge, γ-irradiation, and UV treatment, and to evaluate the toxicity towards green algae, Pseudokirchneriella subcapitata, before and after treatment. Tetracycline (TCN), lincomycin (LMC) and sulfamethazine (SMZ) were used as target compounds. Gamma (γ)-irradiation showed the highest removal efficiency for all target compounds, while UV and activated sludge treatment showed compound-dependent removal efficiencies. TCN and SMZ were well degraded by all three treatment methods. However, LMC showed extremely low removal efficiency for UV and activated sludge treatments. Overall, the algal toxicity after degradation processes was significantly decreased, and was closely correlated to removal efficiency. However, in the case of γ-irradiated TCN, UV and activated sludge treated LMC as well as sludge treated SMZ, the observed toxicity was higher than expected, which indicates the substantial generation of byproducts or transformed compounds of a greater toxicity in the treated sample. Consequently, γ-radiation treatment could be an effective method for removal of recalcitrant compounds such as antibiotics.
authors.affiliation: School of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), 261 Cheomdan-gwagiro, Buk-gu, Gwangju 500-712, Republic of Korea; Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup, Jeonbuk 580-185, Republic of Korea.
authors.forename: Hyun Young
authors.initials: HY
authors.lastname: Kim
authors.forename: Junho
authors.initials: J
authors.lastname: Jeon
authors.forename: Seungho
authors.initials: S
authors.lastname: Yu
authors.forename: Myunjoo
authors.initials: M
authors.lastname: Lee
authors.forename: Tae-Hun
authors.initials: TH
authors.lastname: Kim
authors.forename: Sang D
authors.initials: SD
authors.lastname: Kim
mesh_terms: D000890:Anti-Infective Agents / Q000032:analysis / Q000528:radiation effects*; D005720:Gamma Rays; D012722:Sewage / Q000737:chemistry*; D013418:Sulfamethazine / Q000032:analysis / Q000528:radiation effects; D014466:Ultraviolet Rays; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000528:radiation effects*
chemical_list: D000890:Anti-Infective Agents; D012722:Sewage; D014874:Water Pollutants, Chemical; D013418:Sulfamethazine
keywords: Activated sludge; Antimicrobials; Pseudokirchneriella subcapitata; Toxicity change; UV; γ-irradiation